Chalcogenide material and electronic device including the same

ABSTRACT

A chalcogenide material and an electronic device are provided. The chalcogenide material may include 0.1-5 atomic percent (at %) of silicon, 15-22 at % of germanium, 30-35 at % of arsenic and 40-50 at % of selenium. The electronic device may include a semiconductor memory device, the semiconductor memory device including a first memory cell that includes a first switching element. The first switching element may include a chalcogenide material including 0.1-5 atomic percent (at %) of silicon, 15-22 at % of germanium, 30-35 at % of arsenic, and 40-50 at % of selenium.

CROSS-REFERENCE TO RELATED APPLICATION

This patent document claims priority to Korean Patent Application No.10-2018-0096778, entitled “CHALCOGENIDE MATERIAL AND ELECTRONIC DEVICEINCLUDING THE SAME” and filed on Aug. 20, 2018, which is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

This patent document relates to memory circuits or devices and theirapplications in electronic devices or systems.

BACKGROUND

Recently, as electronic devices or appliances trend towardminiaturization, low power consumption, high performance,multi-functionality, and so on, there is a demand for electronic devicescapable of storing information in various electronic devices orappliances such as a computer, a portable communication device, and soon, and research and development for such electronic devices have beenconducted. Examples of such electronic devices include electronicdevices which can store data using a switching characteristic betweendifferent resistance states according to an applied voltage or current,and can be implemented in various configurations, for example, an RRAM(resistive random access memory), a PRAM (phase change random accessmemory), an FRAM (ferroelectric random access memory), an MRAM (magneticrandom access memory), an E-fuse, etc.

SUMMARY

The disclosed technology in this patent document includes memorycircuits or devices and their applications in electronic devices orsystems and various implementations of an electronic device, in which anelectronic device includes a semiconductor memory (or semiconductormemory device) which can improve characteristics of a selection element.

In one aspect, a chalcogenide material may include 0.1-5 atomic percent(at %) of silicon, 15-22 at % of germanium, 30-35 at % of arsenic, and40-50 at % of selenium.

Implementations of the above chalcogenide material may include one ormore the following.

Content of silicon may be 0.5-4 at %. Content of germanium may be 17-20at %. Content of arsenic may be 31-34 at %. Content of selenium may be43-48 at %.

In another aspect, an electronic device may include a switching elementincluding a chalcogenide material, the chalcogenide material including0.1-5 atomic percent (at %) of silicon, 15-22 at % of germanium, 30-35at % of arsenic, and 40-50 at % of selenium; a first electrodeelectrically coupled to the switching element; and a second electrodeelectrically coupled to the switching element.

Implementations of the above electronic device may include one or morethe following.

The content of silicon may be 0.5-4 at %. The content of germanium maybe 17-20 at %. The content of arsenic may be 31-34 at %. The content ofselenium may be 43-48 at %.

A further another aspect, an electronic device may include asemiconductor memory device wherein the semiconductor memory device mayinclude a first memory cell that includes a first switching element,wherein the first switching element may include a chalcogenide materialincluding 0.1-5 atomic percent (at %) of silicon, 15-22 at % ofgermanium, 30-35 at % of arsenic, and 40-50 at % of selenium.

Implementations of the above electronic device may include one or morethe following.

The semiconductor memory device may further include a second memory cellincluding a second switching element, the second switching elementhaving a chalcogenide material including 0.1-5 atomic percent (at %) ofsilicon, 15-22 at % of germanium, 30-35 at % of arsenic, and 40-50 at %of selenium, and the first memory cell and the second memory cell mayfurther include a first memory layer and a second memory layer,respectively, each of the first and second memory layers switchingbetween different resistance states according to a voltage or a currentapplied thereto. The first switching element and the second switchingelement may control access to the first memory layer and the secondmemory layer, respectively. The semiconductor memory device may includea plurality of memory cells including the first memory cell, thesemiconductor memory device may further include: a plurality of firstlines disposed between a substrate and the plurality of memory cells,each of the plurality of first lines extending in a first direction; anda plurality of second lines disposed over the plurality of memory cells,each of the plurality of second lines extending in a second directionthat crosses the first direction, and wherein the plurality of memorycells are disposed at respective intersections of the first lines andthe second lines. The semiconductor memory device may further include acapping layer disposed over at least side surfaces of the first memorycell. Content of silicon may be 0.5-4 at %. Content of germanium may be17-20 at %. Content of arsenic may be 31-34 at %. Content of seleniummay be 43-48 at %.

The electronic device may further include a microprocessor whichincludes: a control unit configured to receive a signal including acommand from an outside of the microprocessor, and performs extracting,decoding of the command, or controlling input or output of a signal ofthe microprocessor; an operation unit configured to perform an operationbased on a result that the control unit decodes the command; and amemory unit configured to store data for performing the operation, datacorresponding to a result of performing the operation, or an address ofdata for which the operation is performed, wherein the semiconductormemory is part of the memory unit in the microprocessor.

The electronic device may further include a processor which includes: acore unit configured to perform, based on a command inputted from anoutside of the processor, an operation corresponding to the command, byusing data; a cache memory unit configured to store data for performingthe operation, data corresponding to a result of performing theoperation, or an address of data for which the operation is performed;and a bus interface connected between the core unit and the cache memoryunit, and configured to transmit data between the core unit and thecache memory unit, wherein the semiconductor memory is part of the cachememory unit in the processor.

The electronic device may further include a processing system whichincludes: a processor configured to decode a command received by theprocessor and control an operation for information based on a result ofdecoding the command; an auxiliary memory device configured to store aprogram for decoding the command and the information; a main memorydevice configured to call and store the program and the information fromthe auxiliary memory device such that the processor can perform theoperation using the program and the information when executing theprogram; and an interface device configured to perform communicationbetween at least one of the processor, the auxiliary memory device andthe main memory device and the outside, wherein the semiconductor memoryis part of the auxiliary memory device or the main memory device in theprocessing system.

The electronic device may further include a data storage system whichincludes: a storage device configured to store data and conserve storeddata regardless of power supply; a controller configured to controlinput and output of data to and from the storage device according to acommand inputted from an outside; a temporary storage device configuredto temporarily store data exchanged between the storage device and theoutside; and an interface configured to perform communication between atleast one of the storage device, the controller and the temporarystorage device and the outside, wherein the semiconductor memory is partof the storage device or the temporary storage device in the datastorage system.

The electronic device may further include a memory system whichincludes: a memory configured to store data and conserve stored dataregardless of power supply; a memory controller configured to controlinput and output of data to and from the memory according to a commandinputted from an outside; a buffer memory configured to buffer dataexchanged between the memory and the outside; and an interfaceconfigured to perform communication between at least one of the memory,the memory controller and the buffer memory and the outside, wherein thesemiconductor memory is part of the memory or the buffer memory in thememory system.

In still further another aspect, an electronic device may include asemiconductor memory device, wherein the semiconductor memory device mayinclude: a substrate; a plurality of first lines disposed over thesubstrate and each extending in a first direction; a plurality of secondlines extending in a second direction that crosses the first direction;and a plurality of memory cells disposed at respective intersections ofthe plurality of first lines and the plurality of second lines, whereineach of the plurality of the memory cells may include: a variableresistance layer switching between different resistance states accordingto a voltage or a current applied thereto; and a selection element layercontrolling access to the variable resistance layer, and wherein theselection element layer may include a chalcogenide material including0.1-5 atomic percent (at %) of silicon, 15-22 at % of germanium, 30-35at % of arsenic and 40-50 at % of selenium.

Implementations of the above method may include one or more thefollowing.

The variable resistance layer may include any one of a metal oxide, aphase change material, a ferroelectric material, a ferromagneticmaterial, and a combination thereof. The selection element layer mayhave either one of a single-layered structure and a multi-layeredstructure. Each of the plurality of memory cells may further include: alower electrode layer coupled to a lowermost portion of each of theplurality of memory cells and functioning as a transmission path of avoltage or a current between a corresponding one of the plurality offirst lines and a portion other than the lowermost portion of each ofthe memory cells; a middle electrode layer physically separating theselection element layer from the variable resistance layer andelectrically coupling the selection element layer to the variableresistance layer; and an upper electrode layer coupled to an uppermostportion of each of the memory cells and functioning as a transmissionpath of a voltage or a current between a corresponding one of theplurality of second lines and a portion other than the uppermost portionof each of the memory cells. The semiconductor memory device may furtherinclude a capping layer disposed over at least side surfaces of theplurality of memory cells. Content of silicon may be 0.5-4 at %. Contentof germanium may be 17-20 at %. Content of arsenic may be 31-34 at %.Content of selenium may be 43-48 at %.

These and other aspects, implementations and associated advantages aredescribed in greater detail in the drawings, the description and theclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates voltage drift according to Si content in achalcogenide material in accordance with an implementation of thedisclosed technology.

FIG. 2 illustrates a normalized drifted threshold voltage according toSi content in a chalcogenide material in accordance with animplementation of the disclosed technology.

FIG. 3 illustrates a normalized voltage (VFF) according to Si content ina chalcogenide material in accordance with an implementation of thedisclosed technology.

FIG. 4 illustrates a normalized threshold voltage (Vth) according to theSi content in a chalcogenide material in accordance with animplementation of the disclosed technology.

FIG. 5 illustrates an off current (Ioff) according to Si content in achalcogenide material in accordance with an implementation of thedisclosed technology.

FIG. 6 illustrates a normalized threshold voltage (Vth) distributionaccording to Si content in a chalcogenide material in accordance with animplementation of the disclosed technology.

FIG. 7 illustrates a normalized Vth variation before and afterevaluation of endurance according to Si content in a chalcogenidematerial in accordance with an implementation of the disclosedtechnology.

FIG. 8 is a perspective view of a semiconductor memory in accordancewith an implementation of the disclosed technology.

FIGS. 9A to 9D are cross-sectional views illustrating an exemplarysemiconductor memory and a method for fabricating the same in accordancewith an implementation of the disclosed technology.

FIG. 10 is a cross-sectional view illustrating a semiconductor memory inaccordance with an implementation of the disclosed technology.

FIG. 11 is an example of configuration diagram of a microprocessorimplementing memory circuitry based on an implementation of thedisclosed technology.

FIG. 12 is an example of configuration diagram of a processorimplementing memory circuitry based on an implementation of thedisclosed technology.

FIG. 13 is an example of configuration diagram of a system implementingmemory circuitry based on an implementation of the disclosed technology.

FIG. 14 is an example of configuration diagram of a data storage systemimplementing memory circuitry based on an implementation of thedisclosed technology.

FIG. 15 is an example of configuration diagram of a memory systemimplementing memory circuitry based on an implementation of thedisclosed technology.

DETAILED DESCRIPTION

Various examples and implementations of the disclosed technology aredescribed below in detail with reference to the accompanying drawings.

The drawings may not be necessarily to scale and in some instances,proportions of at least some of substrates in the drawings may have beenexaggerated to illustrate certain features of the described examples orimplementations. In presenting a specific example in a drawing ordescription having two or more layers in a multi-layer substrate, therelative positioning relationship of such layers or the sequence ofarranging the layers as shown reflects a particular implementation forthe described or illustrated example and a different relativepositioning relationship or sequence of arranging the layers may bepossible.

In accordance with implementations of the present disclosure, achalcogenide material which is useful for a switching element may beprovided. A chalcogenide is a chemical compound consisting of at leastone chalcogen anion and one or more electropositive materials. Thechalcogenide material may be used as a phase change material or aswitching element depending on a combination of constituent elements andthe contents thereof.

In an implementation of the disclosed technology, a chalcogenidematerial may include 0.1-5 atomic percent (at %) of silicon (Si), 15-22at % of germanium (Ge), 30-35 at % of arsenic (As), and 40-50 at % ofselenium (Se). In another implementation of the disclosed technology, achalcogenide material may include 0.5-4 at % of silicon (Si), 17-20 at %of germanium (Ge), 31-34 at % of arsenic (As), and 43-48 at % ofselenium (Se). In further another implementation of the disclosedtechnology, a chalcogenide material may include about 2.0 at % (e.g.,1.9-2.1 at %, 1.95-2.05 at %, 1.97-2.03 at %, or 1.99-2.01 at %) ofsilicon (Si), about 18.0 at % (e.g., 17.9-18.1 at %, 17.95-18.05 at %,17.97-18.03 at %, or 17.99-18.01 at %) of germanium (Ge), about 32.0 at% (e.g., 31.9-32.1 at %, 31.95-32.05 at %, 31.97-32.03 at %, or31.99-32.01 at %) of arsenic (As) and about 48.0 at % (e.g., 47.9-48.1at %, 47.95-48.05 at %, 47.97-48.03 at %, or 47.99-48.01 at %) ofselenium (Se).

In implementations of the disclosed technology, each constituent elementand its content in the chalcogenide material may be selected such thatan electronic device including the chalcogenide material can exhibitoverall optimal effects in terms of voltage drift, a threshold voltage(Vth), an off current (Ioff), Vth distribution, endurance, and the like.Although it is possible to improve an individual characteristic amongthe above characteristics by suitably selecting any one constituentelement and its content, other characteristics can be deteriorated.Therefore, it is desirable to select optimum constituent elements andadjust their contents, which can lead to the optimum effect inconsideration of the above characteristics together. In implementationsof the disclosed technology, each constituent element and its contentcontained in the chalcogenide material may be determined inconsideration of balancing various aspects of the device performances.

In the chalcogenide material, silicon (Si) and germanium (Ge) may affectvoltage drift (or threshold voltage drift). The voltage drift mayrepresent a change in a threshold voltage (Vth) of a selection elementaccording to a delay time (or a device delay time) of a device thatincludes the selection element. For example, the device delay time is adelay between an input pulse applied to a first end of the device and anoutput pulse generated at a second end of the device in response to theinput pulse, the device including the selection element and a variableresistance element that are coupled to each other in series. As a valueindicating the voltage drift is decreased, the device can exhibit bettercharacteristics. For example, if the device according to animplementation has a difference between a first threshold voltage at afirst device delay time and a second threshold voltage at a seconddevice delay time and the difference is smaller than that of aconventional device, the device performs better than the conventionaldevice. When the device delay time is relatively short, for example, thedevice delay time of 100 ms or less, germanium (Ge) may significantlyaffect reduction in the voltage drift. However, when the device delaytime is relatively long, for example, the device delay time of 100 ms ormore, germanium (Ge) may hardly affect the voltage drift reduction. As aresult, a drift acceleration tendency, which is a phenomenon that a Vthincrease accelerates according to the device delay time, may occur. Forexample, a first increase in the threshold voltage Vth during a firstdevice delay time interval may be greater than a second increase in thethreshold voltage Vth during a second device delay time interval thatprecedes the first device delay time interval. In order to address theseissues, silicon (Si) may be added to decrease a degree of the voltagedrift acceleration when the device delay time is relatively long.However, the degree of voltage drift acceleration may not be decreasedin proportion to an increased amount of the silicon (Si) content.Rather, when the silicon (Si) content is increased, other devicecharacteristics may be deteriorated. Therefore, the silicon (Si) contentmay be determined in such a range as to decrease deterioration of otherdevice characteristics while reducing the voltage drift, as will beexplained below in more detail with reference to FIGS. 1 to 7.

Six materials shown in FIGS. 1 to 7 have the following composition,respectively:

-   -   Material 1: Si 0 at %, Ge 18.5 at %, As 29.7 at %, and Se 51.8        at %;    -   Material 2: Si 3.7 at %, Ge 14.1 at %, As 31.7 at %, and Se 50.5        at %;    -   Material 3: Si 5.0 at %, Ge 14.8 at %, As 31.8 at %, and Se 48.4        at %;    -   Material 4: Si 5.4 at %, Ge 16.1 at %, As 33.5 at %, and Se 45.0        at %;    -   Material 5: Si 6.5 at %, Ge 17.3 at %, As 34.5 at %, and Se 41.7        at %; and    -   Material 6: Si 7.0 at %, Ge 18.0 at %, As 33.2 at %, and Se 41.8        at %.

Referring to FIG. 1, the effect of the silicon (Si) content in achalcogenide material on voltage drift of a threshold voltage (Vth)according to a device delay time will be explained.

FIG. 1 illustrates voltage drift of the threshold voltage according tothe Si content in a chalcogenide material in accordance with animplementation of the disclosed technology. In FIG. 1, the vertical axisrepresents a normalized Vth value and the horizontal axis represents adevice delay time expressed in a logarithmic scale (e.g., a log-10scale). For example, normalized Vth values of a selection elementincluding the chalcogenide material with specific composition in FIG. 1are respective threshold voltages that are normalized by a thresholdvoltage of the selection element with the specific composition at adevice delay time of 100 μs.

Referring to FIG. 1, when the device delay time is shorter than 100 ms,a material (e.g., Material 1) containing no silicon (Si) and materials(e.g., Materials M2, M3, and M4) containing 5.4 at % or less of silicon(Si) have similar trends in a Vth change (or voltage drift). However,when the device delay time is longer than 100 ms, the materialcontaining no silicon (Si) tends to accelerate the Vth change, while thematerials containing 5.4 at % or less of silicon (Si) do notsubstantially accelerate the Vth change. For example, a Vth increase ofMaterial 1 that does not include silicon (Si) during a first devicedelay time interval (e.g., from 1 s to 10 s) is greater than that duringa second device delay time interval (e.g., from 10 ms to 100 ms), whilea Vth increase of Material 2 that includes 3.7 at % of silicon (Si)during the first device delay time interval is not significantlydifferent from that during the second device delay time interval.Meanwhile, when the silicon (Si) content is 6.5 at % or more, thevoltage drift is not substantially accelerated, however, the voltagedrift value itself is significantly increased due to the excessivesilicon (Si) content. For example, a Vth increase of Material 6 thatincludes 7.0 at % of silicon (Si) during the first device delay timeinterval (e.g., from 1 s to 10 s) is not significantly different fromthat during the second device delay time interval (e.g., from 10 ms to100 ms), while the Vth increase of Material 6 during the first seconddevice delay time interval or the second device delay time interval isrelatively large. When the silicon (Si) content is 5.4 at %, the voltagedrift may be decreased, but other device characteristics may bedeteriorated. Accordingly, the silicon (Si) content may be selected toresult in the optimum effect by balancing overall characteristics inconsideration of inhibiting the voltage drift acceleration and obtainingother desirable device characteristics.

In order to determine the optimum silicon (Si) content, at the devicedelay time of 100 ms or more, a threshold voltage (Vth) shift ismeasured to represent the voltage drift acceleration according to thesilicon (Si) content. The results are shown in FIG. 2. In FIG. 2, thedevice delay time is based on 5 decades at the start of 100 μs and thevoltage drift acceleration is represented by the normalized Vth shiftvalue. FIG. 2 illustrates a drifted threshold voltage according to theSi content in a chalcogenide material in accordance with animplementation of the disclosed technology. In FIG. 2, magnitudes of thevoltage shift (drifted threshold voltage) at the Si content of 0 at %,3.7 at %, 5.0 at %, 5.4 at %, 6.5 at % and 7.0 at % are each normalizedby a magnitude of the voltage shift (drifted threshold voltage) at theSi content of 0 at %. In FIG. 2, the vertical axis represents anormalized Vth shift value and the horizontal axis represents thesilicon (Si) content.

Referring to FIG. 2, it is shown that the Vth shift is markedlydecreased at the device delay time of 100 ms or more by increasing thecontent of silicon (Si). Addition of silicon (Si) may decrease the Vthshift, but the Vth shift may not be decreased proportionally to thecontent of the added silicon (Si). When the silicon (Si) content exceeds5.0 at %, the voltage drift acceleration can be substantially inhibited,but the voltage drift value itself is increased, thereby increasing theamount of the Vth shift and deteriorating other device characteristics.Therefore, the silicon (Si) content may be selected to result in theoptimum effect and balance the overall characteristics in considerationof inhibiting the voltage drift acceleration and obtaining otherdesirable device characteristics.

With reference to FIGS. 3 to 7, it will be explained that when thesilicon (Si) content is increased, deterioration of one or more otherdevice characteristics may occur.

FIG. 3 illustrates a normalized voltage (VFF) according to the Sicontent in a chalcogenide material in accordance with an implementationof the disclosed technology. In FIG. 3, the vertical axis represents thenormalized voltage VFF and the horizontal axis represents the silicon(Si) content.

FIG. 4 is a graph showing a normalized threshold voltage (Vth) accordingto the Si content in a chalcogenide material in accordance with animplementation of the disclosed technology. In FIG. 4, the vertical axisis the normalized Vth and the horizontal axis represents the silicon(Si) content.

The VFF may represent a voltage which corresponds to an electricalpotential sufficiently high to cause a selection element to switchbefore operating the selection element. The VFF may refer to a Vth whichappears first. For example, the VFF can be regarded as an initialthreshold voltage of the selection element and subsequent thresholdvoltages of the selection element during a normal operation of theselection element may be lower than the initial threshold voltage. Avalue (e.g., a level) of the VFF may be determined based on a bulkresistance and an interfacial resistance. For example, the interfacialresistance refers to an electrical contact resistance at an interfacebetween the selection element and an electrode to which the VFF isapplied. As the interfacial resistance is decreased, the value of theVFF may become close to a value (e.g., a level) of the Vth. As adifference between the VFF and the Vth is decreased, the device exhibitbetter characteristics.

Referring to FIGS. 3 and 4, when the silicon (Si) content is excessivelylarge, for example, the silicon (Si) content exceeds 5.0 at %, thedifference between the VFF and the Vth is increased. Moreover, when thesilicon (Si) content exceeds 5.0 at %, the Vth may be decreased, andthus a thickness of the selection element that functions as a switchingelement may be significantly increased to obtain a desired value of theVth for the switching element.

As shown in FIGS. 3 and 4, it can be found that, when the silicon (Si)content is excessively large, for example, the silicon (Si) contentexceeds 5.0 at %, the device characteristics associated with the VFF andthe Vth may be deteriorated.

FIG. 5 illustrates an off current (Ioff) according to the Si content ina chalcogenide material in accordance with an implementation of thedisclosed technology. In FIG. 5, the vertical axis represents anormalized off current (Ioff) and the horizontal axis represents the Sicontent. For example, magnitudes of the off current (Ioff) at the Sicontent of 0 at %, 3.7 at %, 5.0 at %, 5.4 at %, 6.5 at %, and 7.0 at %are each normalized by a magnitude of the off current (Ioff) at the Sicontent of 0 at %.

FIG. 6 illustrates a normalized threshold voltage (Vth) distributionaccording to the Si content in a chalcogenide material in accordancewith an implementation of the disclosed technology. In FIG. 6, thevertical axis represents the normalized Vth distribution and thehorizontal axis represents the Si content.

The off current (Ioff) may refer to an electric current in an off stateand affect a sneak current. The sneak current may refer to an electriccurrent that flows in one or more paths other than a desirable path. Forexample, the sneak current may include a current flowing through anunselected memory cell, rather than a selected memory cell. In mostcases, the sneak current may be undesirable, because, for example, thesneak current may cause read margin degradation and increase powerconsumption. When the off current is increased, the sneak current isalso increased, and thus it may be desirable to decrease the off currentin order to improve the device characteristics.

The Vth distribution may represent a degree of change in the Vthaccording to repeated measurements of the Vth. For example, a value ofthe Vth distribution may be a variance of threshold voltages in aplurality of switching elements after a given number of switchingoperations are performed. Each of the plurality of switching elementsmay include a chalcogenide material with specific Si content. Values ofthe Vth distribution at the Si content of 0 at %, 3.7 at %, 5.0 at %,5.4 at %, 6.5 at %, and 7.0 at % may be normalized by a value of the Vthdistribution at the Si content of 0 at %. In order to improve the devicecharacteristics, it may be desirable to decrease the degree of the Vthchange.

Referring to FIGS. 5 and 6, when the silicon (Si) content is excessivelylarge, for example, the silicon (Si) content exceeds 5.0 at %, the offcurrent (Ioff) and the Vth distribution may be significantlydeteriorated.

FIG. 7 illustrates a normalized threshold (Vth) variation before andafter evaluation of endurance according to the Si content in achalcogenide material in accordance with an implementation of thedisclosed technology. In FIG. 7, the vertical axis represents anormalized value of a decreased amount of the Vth and the horizontalaxis represents the Si content.

Endurance of a device may indicate an operating limit of the deviceaccording to an operation cycle. The endurance of the device may beexpressed as the decreased amount of the Vth according to the cycle. Forexample, when a given number of operations for evaluation of enduranceare performed on a selection element including the chalcogenidematerial, a threshold voltage of the selection element may be decreasedcompared to an initial threshold voltage of the selection element. Avalue of the normalized Vth variation in FIG. 7 may be obtained bycalculating a difference between the initial threshold voltage and thethreshold voltage after the given number of operations for evaluation ofendurance have been performed, and then normalizing the calculateddifference. In order to improve the device characteristics, it may bedesirable to reduce the decreased amount of the Vth.

Referring to FIG. 7, it can be found that, if the chalcogenide materialincludes silicon (Si), the decreased amount of the Vth according to thecycle may be increased. When the silicon (Si) content is excessivelylarge, for example, the silicon (Si) content exceeds 5.0 at %, thedecreased amount of the Vth according to the cycle becomes equal to orgreater than a given value (e.g., 1.25 in FIG. 7), thereby causingdeterioration of the endurance.

In the above-described implementations of the disclosed technology, thesilicon (Si) content in the chalcogenide material may be selected so asto balance overall factors affecting the device characteristics andresult in the optimum effect in consideration of not only inhibiting thevoltage drift acceleration (see, FIGS. 1 and 2) but also deteriorationof other device characteristics (see, FIGS. 3 to 7).

In implementations of the disclosed technology, the silicon (Si) contentmay be 0.1-5 at %, or 0.5-4 at %. When the silicon (Si) content in achalcogenide material is less than 0.1 at %, the Vth change according toa device delay time (e.g., the device delay time in FIG. 1) may benonlinearly and significantly increased so that the voltage drift may beaccelerated. When the silicon (Si) content in the chalcogenide materialis greater than 5 at %, deterioration of other device characteristics(e.g., an increase in a difference between the VFF and the Vth, adecrease in Vth stability, an increase in the Ioff, deterioration of theendurance, and an increase in the Vth distribution) may occur.

Germanium (Ge) included in the chalcogenide material may affect thermalstability of the device. Further, Germanium (Ge) may control the voltagedrift by substantially suppressing acceleration of the Vth increase,especially at the device delay time of 100 ms or less.

In implementations of the disclosed technology, the germanium (Ge)content in a chalcogenide material may be 15-22 at %, or 17-20 at %.When the germanium (Ge) content is less than 15 at %, the silicon (Si)content may be increased, thereby causing deterioration of one or moredevice characteristics such as an increase in a difference between theVFF and the Vth, a decrease in Vth stability, an increase in the Ioff,deterioration of the endurance, an increase in the Vth distribution.When the germanium (Ge) content is greater than 22 at %, the thermalstability of the device may be increased, but a value of the voltagedrift may be relatively large.

Arsenic (As) included in the chalcogenide material may contribute toforming an amorphous structure of the chalcogenide material.

In implementations of the disclosed technology, the arsenic (As) contentmay be 30-35 at %, or 31-34 at %. When the arsenic (As) content is lessthan 30 at %, a switching operation of a device including thechalcogenide material may become unstable. When the arsenic (As) contentis greater than 35 at %, content of each of other constituent elementsmay become relatively low due to the excessive arsenic (As) content,thereby resulting in deterioration of the device characteristics.

Selenium (Se) included in the chalcogenide material may have aninfluence on a band gap energy of the device to control a sneak current.Also, selenium (Se) may affect the voltage determination. As the bandgap energy is increased, the off current (Ioff) may be decreased,thereby reducing the sneak current.

In implementations of the disclosed technology, the selenium (Se)content may be 40-50 at %, or 43-48 at %. When the selenium (Se) contentis less than 40 at %, the device may not function properly due to theexcessively low voltage. When the selenium (Se) content is greater than50 at %, a decrease rate of the Vth according to the cycle is increased,thereby deteriorating the endurance.

The chalcogenide material in accordance with the above-describedimplementations may include silicon (Si), germanium (Ge), arsenic (As),and selenium (Se) as constituent elements, wherein the content of eachconstituent element may be selected to exhibit the optimum effect inconsideration of the overall characteristics of the device. For example,the silicon (Si) content may be selected to substantially inhibit thevoltage drift acceleration and reduce deterioration of other devicecharacteristics.

The chalcogenide material may be prepared by various methods such asphysical vapor deposition (PVD), chemical vapor deposition (CVD), atomiclayer deposition (ALD), ion implantation, and the like.

In an implementation, a Si—Ge—As—Se chalcogenide material may be formedthrough a physical deposition process by using a SiGeAsSe alloy target,for example, a sputtering process.

In another implementation, a Si—Ge—As—Se chalcogenide material may beformed through a physical deposition process by using a Si target and aGeAsSe alloy target, for example, a co-sputtering process.

In further another implementation, a Si—Ge—As—Se chalcogenide materialmay be formed by incorporating Si into a Ge—As—Se material using asputtering process, an ion implantation process, or both.

In still another implementation, a Si—Ge—As—Se chalcogenide material maybe formed by depositing a Si layer and a GeAsSe layer and performing aheat treatment to cause a reaction between the Si layer and the GeAsSelayer.

In still further another implementation, a Si—Ge—As—Se chalcogenidematerial may be formed by depositing a plurality of Si layers and aplurality of GeAsSe layers and performing a heat treatment to cause areaction between the Si layers and the GeAsSe layers.

An element including a chalcogenide material in accordance with animplementation may function as a switching element according to typesand composition of constituent elements. The switching element using thechalcogenide may include an ovonic memory switching (OMS) element and anovonic threshold switching (OTS) element. For the OMS element, when apulse is applied to the OMS element, the phase of a material is changed.When a pulse is applied to the OTS element, the electricalcharacteristic is changed from a nonconductor state to a conductor statein a single phase (usually an amorphous phase), and when the pulse isremoved, it returns to its original nonconductor state. The OTS elementmay have a high resistance in response to a voltage less than a giventhreshold voltage (Vth). When a voltage greater than the Vth is applied,a current flows through the OTS element at a relatively low voltage thatis substantially constant and the OTS element exhibits a low impedance.When the current through the OTS element becomes lower than a holdingcurrent, the OTS element returns to a high-impedance condition. This I-Vcharacteristics of the OTS element may be substantially symmetrical.

Hereinafter, an electronic device including a switching elementincluding the chalcogenide material in accordance with theabove-described implementations will be explained.

FIG. 8 is a perspective view of a semiconductor memory in accordancewith an implementation of the disclosed technology.

The semiconductor memory (or semiconductor memory device) in accordancewith the implementation in FIG. 8 of the present disclosure may have across-point structure which includes first lines 110 each extending in afirst direction, second lines 150 located over the first lines 110 andeach extending in a second direction crossing the first direction, andmemory cells 120 located between the first lines 110 and the secondlines 150. The memory cells 120 are disposed at respective intersectionsof the first lines 110 and the second lines 150.

FIGS. 9A to 9D are cross-sectional views illustrating a semiconductormemory and a method for fabricating the semiconductor memory inaccordance with an implementation of the disclosed technology.

For example, FIG. 9D is a cross-sectional view of a portion of thesemiconductor device taken along line A-A′ of FIG. 8.

Referring to FIG. 9A, a substrate 100 including given structures (notshown) may be provided. For example, the given structures may includeone or more transistors for controlling the first lines 110, the secondlines 150, or the first and second lines 110 and 150 of FIGS. 8 and 9D,which are formed over the substrate 100.

Then, the first lines 110 each extending in a first direction (e.g., ahorizontal direction in FIG. 9A) may be formed over the substrate 100.The first lines 110 may have a single-layered structure or amulti-layered structure, and may include a conductive material such as ametal, a metal nitride, etc. The first lines 110 may be formed bydepositing a layer that includes the conductive material and patterningthe deposited layer. Spaces between the first lines 110 may be filledwith an insulating material (not shown).

Then, a plurality of memory cells 120 may be formed over the first lines110. In the implementation shown in FIG. 9A, each of the plurality ofmemory cells 120 may have a pillar shape. The plurality of memory cells120 may be arranged in a matrix having rows and columns. The rows eachextend along the first direction and the columns each extend along asecond direction crossing the first direction. The memory cells 120 maybe disposed in respective intersection regions between the first lines110 and second lines 150. An intersection region between one of thefirst lines 110 and one of the second lines 150 is defined, for example,as a three-dimensional region where the first line 110 and the secondline 150 overlap each other in a third direction (e.g., a verticaldirection in FIG. 9A) that crosses the first and second directions. Inan implementation, each of the memory cells 120 may have a size that issubstantially equal to or smaller than that of the intersection regionbetween each corresponding pair of the first lines 110 and the secondlines 150. In another implementation, each of the memory cells 120 mayhave a size that is larger than that of the intersection region betweeneach corresponding pair of the first lines 110 and the second lines 150.

The memory cells 120 may be formed by depositing a plurality of materiallayers (not shown) over a structure including the first lines 110 andthe insulating material (not shown), forming a plurality of hard maskpatterns 130 over the plurality of material layers, and etching thematerial layers using the hard mask patterns 130 as an etching barrier.Therefore, each of the hard mask patterns 130 has sidewallssubstantially aligned with sidewalls of each of the corresponding memorycells 120.

The hard mask patterns 130 may function as an etching barrier duringetching the material layers (not shown) for forming the memory cells 120and include one or more of various materials having etch selectivitywith respect to the memory cells 120. For example, each of the hard maskpatterns 130 may have a single-layered structure or a multi-layeredstructure and include an insulating material such as a silicon oxide, asilicon nitride, a silicon oxynitride, etc.

Also, in this implementation of FIG. 9A, each of the plurality of memorycells 120 may include a lower electrode layer 121, a selection elementlayer 123, a middle electrode layer 125, a variable resistance layer127, and an upper electrode layer 129, which are sequentially stacked.

Specifically, the lower electrode layer 121 may be located at alowermost portion of each of the memory cells 120 and function as atransmission path of a voltage or a current between a corresponding oneof the first lines 110 and the remaining portion (e.g., the elements123, 125, 127, and 129) of each of the memory cells 120. The middleelectrode layer 125 may physically separate the selection element layer123 from the variable resistance layer 127, and electrically couple theselection element layer 123 to the variable resistance layer 127. Forexample, a current flow through the selection element layer 123, themiddle electrode layer 125, and the variable resistance layer 127, whena voltage level across the selection element layer 123 is equal to orgreater than a given threshold voltage. The upper electrode layer 129may be located at an uppermost portion of each of the memory cells 120and function as a transmission path of a voltage or a current between acorresponding one of the second lines 150 of FIG. 9D and the remainingportion (e.g., the elements 121, 123, 125, and 127) of each of thememory cells 120. Each of the lower electrode layer 121, the middleelectrode layer 125, and the upper electrode layer 129 may have asingle-layered structure or a multi-layered structure and include aconductive material such as a metal, a metal nitride, a conductivecarbon material, etc.

The selection element layer 123 may control access to the variableresistance layer 127. That is, the selection element layer 123 mayfunction as a switching element and have a selection elementcharacteristic, which substantially prevents a current from passingthrough the selection element layer 123 when a magnitude of an appliedvoltage or an applied current is lower than a critical value (or athreshold value), and causes a current to pass through the selectionelement layer 123 when a magnitude of the applied voltage or the appliedcurrent is substantially equal to or greater than the critical value.For example, a magnitude of the current passing through the selectionelement layer 123 is proportional to a magnitude of the voltage orcurrent applied to the selection element layer 123. The selectionelement layer 123 may have a single-layered structure, or amulti-layered structure that exhibits the selection elementcharacteristic using a combination of two or more layers.

For example, the selection element layer 123 may include thechalcogenide material in accordance with the above-describedimplementations. Specifically, in an implementation of the disclosedtechnology, the selection element layer 123 may include a chalcogenidematerial including 0.1-5 at % of silicon (Si), 15-22 at % of germanium(Ge), 30-35 at % of arsenic (As), and 40-50 at % of selenium (Se).Moreover, in an implementation of the disclosed technology, theselection element layer 123 may include a chalcogenide materialincluding 0.5-4 at % of silicon (Si), 17-20 at % of germanium (Ge),31-34 at % of arsenic (As), and 43-48 at % of selenium (Se). Further, inan implementation of the disclosed technology, the selection elementlayer 123 may include a chalcogenide material including about 2.0 at %of silicon (Si), about 18.0 at % of germanium (Ge), about 32.0 at % ofarsenic (As), and about 48.0 at % of selenium (Se). Such a chalcogenidematerial has been explained in detail in the above-describedimplementations, the detailed explanation for the chalcogenide materialis omitted for the interest of brevity.

As described above, the chalcogenide material included in the selectionelement layer 123 may include silicon (Si), germanium (Ge), arsenic(As), and selenium (Se) as constituent elements, wherein the content ofeach constituent element may be selected to exhibit the optimum effectin consideration of the overall characteristics of the device. Forexample, the silicon (Si) content may be selected to substantiallyinhibit the voltage drift acceleration and reduce deterioration of otherdevice characteristics. Therefore, it is possible to effectivelysuppress the voltage drift acceleration at both of a relatively longdelay time as well as a relatively short delay time and substantiallyprevent deterioration of other device characteristics, resulting insuperior device characteristics and improved reliability of the device.

The variable resistance layer 127 may switch between differentresistance states according to a voltage or a current applied to thevariable resistance layer 127 through the upper electrode layer 129 andthe middle electrode layer 125, thereby storing data having differentvalues. For example, when the variable resistance layer 127 is in a lowresistance state, data having a first logic value of ‘1’ may be storedin the variable resistance layer 127. On the other hand, when thevariable resistance layer 127 is in a high resistance state, data havinga second logic value of ‘0’ may be stored in the variable resistancelayer 127. The variable resistance layer 127 may include one or more ofvarious materials that are used in RRAM, PRAM, FRAM, MRAM, or the like.For example, the variable resistance layer 127 may include any of metaloxides, such as transition metal oxides or perovskite-based materials;phase-change materials, such as chalcogenide-based materials;ferroelectric materials, ferromagnetic materials; and the like. Thevariable resistance layer 127 may have a single-layered structure, or amulti-layered structure that shows a variable resistance characteristicby a combination of two or more layers. However, other implementationsare also possible. For example, the memory cells 120 may include amemory layer, which can store data in different ways from theabove-described variable resistance layer 127.

In the implementation shown in FIG. 9A, each of the memory cells 120includes the lower electrode layer 121, the selection element layer 123,the middle electrode layer 125, the variable resistance layer 127, andthe upper electrode layer 129. However, implementations of the presentpatent document are not limited thereto, and the memory cells 120 mayhave various structures. In some implementations, one or more of thelower electrode layer 121, the middle electrode layer 125, and the upperelectrode layer 129 may be omitted. In some implementations, the stackedorder of the selection element layer 123 and the variable resistancelayer 127 may be reversed with respect to the orientation shown in FIG.9A, such that the selection element layer 123 may be disposed over thevariable resistance layer 127. In some implementations, in addition tothe layers 121, 123, 125, 127, and 129 shown in FIG. 9A, the memorycells 120 may further include one or more layers (not shown) forenhancing characteristics of the memory cells 120, improving fabricatingprocesses, or both.

A neighboring pair of the plurality of memory cells 120 may be spacedapart from each other at a given interval, and trenches may be presentbetween the plurality of memory cells 120. In an implementation, thegiven interval is a predetermined interval, and a trench between aneighboring pair of the plurality of memory cells 120 may have a heightto width ratio (or an aspect ratio) in a range from 1:1 to 40:1, from10:1 to 40:1, from 10:1 to 20:1, from 5:1 to 10:1, from 10:1 to 15:1,from 1:1 to 25:1, from 1:1 to 30:1, from 1:1 to 35:1, or from 1:1 to45:1.

In some implementations, the trench may have sidewalls that aresubstantially perpendicular to an upper surface of the substrate 100. Insome implementations, neighboring trenches may be spaced apart from eachother by substantially the same distance. For example, a first pair oftrenches neighboring each other in a first direction (e.g., the firstdirection of FIG. 8) may be spaced apart from each other bysubstantially the same distance as a second pair of trenches neighboringeach other in a second direction (e.g., the second direction of FIG. 8).In some implementations, distances between the neighboring trenches mayvary.

Referring to FIG. 9B, an interlayer dielectric layer 140 may be formedover the structure illustrated in FIG. 9A. The interlayer dielectriclayer 140 may include various insulating materials such as a siliconoxide, a silicon nitride, a silicon oxynitride, and the like. Moreover,the interlayer dielectric layer 140 may be formed along a lower profile.For example, the interlayer dielectric layer 140 is formed over thefirst lines 110, sidewalls of the memory cells 120, and upper surfacesand sidewalls of the hard mask patterns 130.

Referring to FIG. 9C, a planarization process may be performed on theinterlayer dielectric layer 140 until the upper electrode 129 isexposed. The planarization process may be performed by a chemicalmechanical polishing (CMP) process, an etch process, a cleaning process,or any suitable planarization process. Since the planarization processis performed until upper surfaces of the upper electrode layers 129 ofthe memory cells 120 are exposed, the hard mask pattern 130 may beremoved by the planarization process.

Referring to FIG. 9D, a plurality of second lines 150 may be formed overthe memory cells 120 and the interlayer dielectric layer 140. Theplurality of second lines 150 may be respectively coupled to the uppersurfaces of the memory cells 120. Each of the plurality of second lines150 extends in the second direction crossing the first direction. Forexample, the second direction may be perpendicular to the line A-A′ ofFIG. 8. Each of the second lines 150 may have a single-layer structureor a multi-layer structure, and include a conductive material, such asany of a metal, a metal nitride, and the like. The second lines 150 maybe formed by depositing a conductive material and patterning thedeposited material. Spaces between neighboring second lines 150 may befilled with an insulating material (not shown).

Through the processes as described above, the semiconductor memory shownin FIG. 9D may be fabricated.

In the implementation shown in FIG. 9D, the semiconductor memory mayinclude the memory cells 120 disposed at intersection regions betweenthe first lines 110 each extending in the first direction and the secondlines 150 each extending in the second direction. In an implementation,the selection element layer 123 of each of the memory cells 120 mayinclude a chalcogenide material including 0.1-5 at % of silicon (Si),15-22 at % of germanium (Ge), 30-35 at % of arsenic (As), and 40-50 at %of selenium (Se). In an implementation, the selection element layer 123of each of the memory cells 120 may include a chalcogenide materialincluding 0.5-4 at % of silicon (Si), 17-20 at % of germanium (Ge),31-34 at % of arsenic (As), and 43-48 at % of selenium (Se).

The memory cells 120 may store data having different values according toa voltage or current that is applied thereto through the first lines 110and the second lines 150. In particular, when the memory cells 120 eachinclude variable resistance elements, each of the memory cells 120 maystore data by switching between different resistance states.

One or more of the first lines 110 each may function as a word line andone more of the second lines 150 each may function as a bit line, andvice versa.

In the semiconductor memory of FIG. 9D fabricated by a method accordingto an implementation of the present disclosure, the selection elementlayer 123 of the memory cells 120 includes the chalcogenide materialhaving specific composition of four components so that the optimumeffects can be exhibited in terms of various aspects of devicecharacteristics such as voltage drift, a Vth, a VFF, an Ioff, Vthdistribution, endurance, and the like.

FIG. 10 is a cross-sectional view illustrating a semiconductor memory inaccordance with an implementation of the disclosed technology. Detaileddescriptions of parts that are substantially the same as those of theimplementation described above with reference to FIGS. 9A to 9D will beomitted for the interest of brevity.

Referring to FIG. 10, a capping layer 160 may be further formed onsidewalls of the memory cells 120 and over the first lines 110. Thecapping layer 160 may function to protect the memory cells 120, and havea single-layered structure or a multi-layered structure includingvarious insulating materials such as a silicon nitride and the like.

The capping layer 160 may be formed by forming a material layer for thecapping layer 160 over the structure of FIG. 9A, for example, onsidewalls of the memory cells 120 and sidewalls and upper surfaces ofthe hard mask pattern 130 and performing the processes of FIGS. 9B to9D.

As a result, the first lines 110 each extending in a first direction(e.g., the first direction of FIG. 8) and the second lines 150 eachextending in a second direction (e.g., the second direction of FIG. 8)are formed over the substrate 100 and the memory cells 120 may bedisposed in respective intersection regions between the first lines 110and the second lines 150. In an implementation, the selection elementlayer 123 of each of the memory cells 120 may include the chalcogenidematerial including 0.1-5 at % of silicon (Si), 15-22 at % of germanium(Ge), 30-35 at % of arsenic (As), and 40-50 at % of selenium (Se). In animplementation, the selection element layer 123 of each of the memorycells 120 may include a chalcogenide material including 0.5-4 at % ofsilicon (Si), 17-20 at % of germanium (Ge), 31-34 at % of arsenic (As),and 43-48 at % of selenium (Se).

The sidewalls of the memory cells 120 may be in direct contact with thecapping layer 160. The capping layer 160 may include an insulatingmaterial and function to protect the memory cells 120.

In the implementations shown in FIGS. 8 to 10, the semiconductor memoryhaving a single-layer cross-point structure has been described. However,in another implementation, a semiconductor memory may have a multi-layercross-point structure in which two or more cross-point structures may bestacked. Each of the cross-point structures may include first lines 110,second lines 150, and memory cells 120 located at respectiveintersections between the first lines 110 and the second lines 150.

Memory circuits or semiconductor devices in accordance withimplementations based on the disclosed technology can be used in a rangeof devices or systems. FIGS. 11 to 15 provide some examples of devicesor systems that can implement the memory circuits disclosed herein.

FIG. 11 is an example of configuration diagram of a microprocessorimplementing memory circuitry based on the disclosed technology.

Referring to FIG. 11, a microprocessor 1000 may perform tasks forcontrolling and tuning a series of processes of receiving data fromvarious external devices, processing the data, and outputting processingresults to external devices. The microprocessor 1000 may include amemory unit 1010, an operation unit 1020, a control unit 1030, and soon. The microprocessor 1000 may be various data processing units such asa central processing unit (CPU), a graphic processing unit (GPU), adigital signal processor (DSP) and an application processor (AP).

The memory unit 1010 is a part which stores data in the microprocessor1000, as a processor register, register or the like. The memory unit1010 may include a data register, an address register, a floating pointregister and so on. Besides, the memory unit 1010 may include variousregisters. The memory unit 1010 may perform the function of temporarilystoring data for which operations are to be performed by the operationunit 1020, result data of performing the operations and addresses wheredata for performing of the operations are stored.

The memory unit 1010 may include one or more of the above-describedsemiconductor devices in accordance with the implementations. Forexample, the memory unit 1010 may include a plurality of memory cellseach including a switching element, wherein the switching elementincludes a chalcogenide material including 0.1-5 atomic percent (at %)of silicon, 15-22 at % of germanium, 30-35 at % of arsenic and 40-50 at% of selenium. Through this, data storage characteristics of the memoryunit 1010 may be improved. As a consequence, operating characteristicsof the microprocessor 1000 may be improved.

The operation unit 1020 may perform four arithmetical operations orlogical operations according to results that the control unit 1030decodes commands. The operation unit 1020 may include at least onearithmetic logic unit (ALU) and so on.

The control unit 1030 may receive signals from the memory unit 1010, theoperation unit 1020 and an external device of the microprocessor 1000,perform extraction, decoding of commands, and controlling input andoutput of signals of the microprocessor 1000, and execute processingrepresented by programs.

The microprocessor 1000 according to this implementation mayadditionally include a cache memory unit 1040 which can temporarilystore data to be inputted from an external device other than the memoryunit 1010 or to be outputted to an external device. In this case, thecache memory unit 1040 may exchange data with the memory unit 1010, theoperation unit 1020 and the control unit 1030 through a bus interface1050.

FIG. 12 is an example of configuration diagram of a processorimplementing memory circuitry based on an implementation of thedisclosed technology.

Referring to FIG. 12, a processor 1100 may improve performance andrealize multi-functionality by including various functions other thanthose of a microprocessor which performs tasks for controlling andtuning a series of processes of receiving data from various externaldevices, processing the data, and outputting processing results toexternal devices. The processor 1100 may include a core unit 1110 whichserves as the microprocessor, a cache memory unit 1120 which serves tostoring data temporarily, and a bus interface 1130 for transferring databetween internal and external devices. The processor 1100 may includevarious system-on-chips (SoCs) such as a multi-core processor, a graphicprocessing unit (GPU) and an application processor (AP).

The core unit 1110 of this implementation is a part which performsarithmetic logic operations for data inputted from an external device,and may include a memory unit 1111, an operation unit 1112 and a controlunit 1113.

The memory unit 1111 is a part which stores data in the processor 1100,as a processor register, a register or the like. The memory unit 1111may include a data register, an address register, a floating pointregister and so on. Besides, the memory unit 1111 may include variousregisters. The memory unit 1111 may perform the function of temporarilystoring data for which operations are to be performed by the operationunit 1112, result data of performing the operations and addresses wheredata for performing of the operations are stored. The operation unit1112 is a part which performs operations in the processor 1100. Theoperation unit 1112 may perform four arithmetical operations, logicaloperations, according to results that the control unit 1113 decodescommands, or the like. The operation unit 1112 may include at least onearithmetic logic unit (ALU) and so on. The control unit 1113 may receivesignals from the memory unit 1111, the operation unit 1112 and anexternal device of the processor 1100, perform extraction, decoding ofcommands, controlling input and output of signals of processor 1100, andexecute processing represented by programs.

The cache memory unit 1120 is a part which temporarily stores data tocompensate for a difference in data processing speed between the coreunit 1110 operating at a high speed and an external device operating ata low speed. The cache memory unit 1120 may include a primary storagesection 1121, a secondary storage section 1122 and a tertiary storagesection 1123. In general, the cache memory unit 1120 includes theprimary and secondary storage sections 1121 and 1122, and may includethe tertiary storage section 1123 in the case where high storagecapacity is required. As the occasion demands, the cache memory unit1120 may include an increased number of storage sections. That is tosay, the number of storage sections which are included in the cachememory unit 1120 may be changed according to a design. The speeds atwhich the primary, secondary and tertiary storage sections 1121, 1122and 1123 store and discriminate data may be the same or different. Inthe case where the speeds of the respective storage sections 1121, 1122and 1123 are different, the speed of the primary storage section 1121may be largest. At least one storage section of the primary storagesection 1121, the secondary storage section 1122 and the tertiarystorage section 1123 of the cache memory unit 1120 may include one ormore of the above-described semiconductor devices in accordance with theimplementations. For example, the cache memory unit 1120 may include aplurality of memory cells each including a switching element, whereinthe switching element includes a chalcogenide material including 0.1-5atomic percent (at %) of silicon, 15-22 at % of germanium, 30-35 at % ofarsenic and 40-50 at % of selenium. Through this, data storagecharacteristics of the cache memory unit 1120 may be improved. As aconsequence, operating characteristics of the processor 1100 may beimproved.

Although it was shown in FIG. 10 that all the primary, secondary andtertiary storage sections 1121, 1122 and 1123 are configured inside thecache memory unit 1120, it is to be noted that all the primary,secondary and tertiary storage sections 1121, 1122 and 1123 of the cachememory unit 1120 may be configured outside the core unit 1110 and maycompensate for a difference in data processing speed between the coreunit 1110 and the external device. Meanwhile, it is to be noted that theprimary storage section 1121 of the cache memory unit 1120 may bedisposed inside the core unit 1110 and the secondary storage section1122 and the tertiary storage section 1123 may be configured outside thecore unit 1110 to strengthen the function of compensating for adifference in data processing speed. In another implementation, theprimary and secondary storage sections 1121, 1122 may be disposed insidethe core units 1110 and tertiary storage sections 1123 may be disposedoutside core units 1110.

The bus interface 1130 is a part which connects the core unit 1110, thecache memory unit 1120 and external device and allows data to beefficiently transmitted.

The processor 1100 according to this implementation may include aplurality of core units 1110, and the plurality of core units 1110 mayshare the cache memory unit 1120. The plurality of core units 1110 andthe cache memory unit 1120 may be directly connected or be connectedthrough the bus interface 1130. The plurality of core units 1110 may beconfigured in the same way as the above-described configuration of thecore unit 1110. In the case where the processor 1100 includes theplurality of core unit 1110, the primary storage section 1121 of thecache memory unit 1120 may be configured in each core unit 1110 incorrespondence to the number of the plurality of core units 1110, andthe secondary storage section 1122 and the tertiary storage section 1123may be configured outside the plurality of core units 1110 in such a wayas to be shared through the bus interface 1130. The processing speed ofthe primary storage section 1121 may be larger than the processingspeeds of the secondary and tertiary storage section 1122 and 1123. Inanother implementation, the primary storage section 1121 and thesecondary storage section 1122 may be configured in each core unit 1110in correspondence to the number of the plurality of core units 1110, andthe tertiary storage section 1123 may be configured outside theplurality of core units 1110 in such a way as to be shared through thebus interface 1130.

The processor 1100 according to this implementation may further includean embedded memory unit 1140 which stores data, a communication moduleunit 1150 which can transmit and receive data to and from an externaldevice in a wired or wireless manner, a memory control unit 1160 whichdrives an external memory device, and a media processing unit 1170 whichprocesses the data processed in the processor 1100 or the data inputtedfrom an external input device and outputs the processed data to anexternal interface device and so on. Besides, the processor 1100 mayinclude a plurality of various modules and devices. In this case, theplurality of modules which are added may exchange data with the coreunits 1110 and the cache memory unit 1120 and with one another, throughthe bus interface 1130.

The embedded memory unit 1140 may include not only a volatile memory butalso a nonvolatile memory. The volatile memory may include a DRAM(dynamic random access memory), a mobile DRAM, an SRAM (static randomaccess memory), and a memory with similar functions to above mentionedmemories, and so on. The nonvolatile memory may include a ROM (read onlymemory), a NOR flash memory, a NAND flash memory, a phase change randomaccess memory (PRAM), a resistive random access memory (RRAM), a spintransfer torque random access memory (STTRAM), a magnetic random accessmemory (MRAM), a memory with similar functions.

The communication module unit 1150 may include a module capable of beingconnected with a wired network, a module capable of being connected witha wireless network and both of them. The wired network module mayinclude a local area network (LAN), a universal serial bus (USB), anEthernet, power line communication (PLC) such as various devices whichsend and receive data through transmit lines, and so on. The wirelessnetwork module may include Infrared Data Association (IrDA), codedivision multiple access (CDMA), time division multiple access (TDMA),frequency division multiple access (FDMA), a wireless LAN, Zigbee, aubiquitous sensor network (USN), Bluetooth, radio frequencyidentification (RFID), long term evolution (LTE), near fieldcommunication (NFC), a wireless broadband Internet (Wibro), high speeddownlink packet access (HSDPA), wideband CDMA (WCDMA), ultra wideband(UWB) such as various devices which send and receive data withouttransmit lines, and so on.

The memory control unit 1160 is to administrate and process datatransmitted between the processor 1100 and an external storage deviceoperating according to a different communication standard.

The memory control unit 1160 may include various memory controllers, forexample, devices which may control IDE (Integrated Device Electronics),SATA (Serial Advanced Technology Attachment), SCSI (Small ComputerSystem Interface), RAID (Redundant Array of Independent Disks), an SSD(solid state disk), eSATA (External SATA), PCMCIA (Personal ComputerMemory Card International Association), a USB (universal serial bus), asecure digital (SD) card, a mini secure digital (mSD) card, a microsecure digital (micro SD) card, a secure digital high capacity (SDHC)card, a memory stick card, a smart media (SM) card, a multimedia card(MMC), an embedded MMC (eMMC), a compact flash (CF) card, and so on.

The media processing unit 1170 may process the data processed in theprocessor 1100 or the data inputted in the forms of image, voice andothers from the external input device and output the data to theexternal interface device. The media processing unit 1170 may include agraphic processing unit (GPU), a digital signal processor (DSP), a highdefinition audio device (HD audio), a high definition multimediainterface (HDMI) controller, and so on.

FIG. 13 is an example of configuration diagram of a system implementingmemory circuitry based on an implementation of the disclosed technology.

Referring to FIG. 13, a system 1200 as an apparatus for processing datamay perform input, processing, output, communication, storage, etc. toconduct a series of manipulations for data. The system 1200 may includea processor 1210, a main memory device 1220, an auxiliary memory device1230, an interface device 1240, and so on. The system 1200 of thisimplementation may be various electronic systems which operate usingprocessors, such as a computer, a server, a PDA (personal digitalassistant), a portable computer, a web tablet, a wireless phone, amobile phone, a smart phone, a digital music player, a PMP (portablemultimedia player), a camera, a global positioning system (GPS), a videocamera, a voice recorder, a telematics, an audio visual (AV) system, asmart television, and so on.

The processor 1210 may decode inputted commands and processes operation,comparison, etc. for the data stored in the system 1200, and controlsthese operations. The processor 1210 may include a microprocessor unit(MPU), a central processing unit (CPU), a single/multi-core processor, agraphic processing unit (GPU), an application processor (AP), a digitalsignal processor (DSP), and so on.

The main memory device 1220 is a storage which can temporarily store,call and execute program codes or data from the auxiliary memory device1230 when programs are executed and can conserve memorized contents evenwhen power supply is cut off. The main memory device 1220 may include aplurality of memory cells each including a switching element, whereinthe switching element includes a chalcogenide material including 0.1-5atomic percent (at %) of silicon, 15-22 at % of germanium, 30-35 at % ofarsenic and 40-50 at % of selenium. Through this, data storagecharacteristics of the main memory device 1220 may be improved. As aconsequence, operating characteristics of the system 1200 may beimproved.

Also, the main memory device 1220 may further include a static randomaccess memory (SRAM), a dynamic random access memory (DRAM), and so on,of a volatile memory type in which all contents are erased when powersupply is cut off. Unlike this, the main memory device 1220 may notinclude the semiconductor devices according to the implementations, butmay include a static random access memory (SRAM), a dynamic randomaccess memory (DRAM), and so on, of a volatile memory type in which allcontents are erased when power supply is cut off.

The auxiliary memory device 1230 is a memory device for storing programcodes or data. While the speed of the auxiliary memory device 1230 isslower than the main memory device 1220, the auxiliary memory device1230 can store a larger amount of data. The auxiliary memory device 1230may include one or more of the above-described semiconductor devices inaccordance with the implementations. For example, the auxiliary memorydevice 1230 may include a plurality of memory cells each including aswitching element, wherein the switching element includes a chalcogenidematerial including 0.1-5 atomic percent (at %) of silicon, 15-22 at % ofgermanium, 30-35 at % of arsenic and 40-50 at % of selenium. Throughthis, data storage characteristics of the auxiliary memory device 1230may be improved. As a consequence, operating characteristics of thesystem 1200 may be improved.

Also, the auxiliary memory device 1230 may further include a datastorage system (see the reference numeral 1300 of FIG. 14) such as amagnetic tape using magnetism, a magnetic disk, a laser disk usingoptics, a magneto-optical disc using both magnetism and optics, a solidstate disk (SSD), a USB memory (universal serial bus memory), a securedigital (SD) card, a mini secure digital (mSD) card, a micro securedigital (micro SD) card, a secure digital high capacity (SDHC) card, amemory stick card, a smart media (SM) card, a multimedia card (MMC), anembedded MMC (eMMC), a compact flash (CF) card, and so on. Unlike this,the auxiliary memory device 1230 may not include the semiconductordevices according to the implementations, but may include data storagesystems (see the reference numeral 1300 of FIG. 14) such as a magnetictape using magnetism, a magnetic disk, a laser disk using optics, amagneto-optical disc using both magnetism and optics, a solid state disk(SSD), a USB memory (universal serial bus memory), a secure digital (SD)card, a mini secure digital (mSD) card, a micro secure digital (microSD) card, a secure digital high capacity (SDHC) card, a memory stickcard, a smart media (SM) card, a multimedia card (MMC), an embedded MMC(eMMC), a compact flash (CF) card, and so on.

The interface device 1240 may be to perform exchange of commands anddata between the system 1200 of this implementation and an externaldevice. The interface device 1240 may be a keypad, a keyboard, a mouse,a speaker, a mike, a display, various human interface devices (HIDs), acommunication device, and so on. The communication device may include amodule capable of being connected with a wired network, a module capableof being connected with a wireless network and both of them. The wirednetwork module may include a local area network (LAN), a universalserial bus (USB), an Ethernet, power line communication (PLC), such asvarious devices which send and receive data through transmit lines, andso on. The wireless network module may include Infrared Data Association(IrDA), code division multiple access (CDMA), time division multipleaccess (TDMA), frequency division multiple access (FDMA), a wirelessLAN, Zigbee, a ubiquitous sensor network (USN), Bluetooth, radiofrequency identification (RFID), long term evolution (LTE), near fieldcommunication (NFC), a wireless broadband Internet (Wibro), high speeddownlink packet access (HSDPA), wideband CDMA (WCDMA), ultra wideband(UWB), such as various devices which send and receive data withouttransmit lines, and so on.

FIG. 14 is an example of configuration diagram of a data storage systemimplementing memory circuitry based on an implementation of thedisclosed technology.

Referring to FIG. 14, a data storage system 1300 may include a storagedevice 1310 which has a nonvolatile characteristic as a component forstoring data, a controller 1320 which controls the storage device 1310,an interface 1330 for connection with an external device, and atemporary storage device 1340 for storing data temporarily. The datastorage system 1300 may be a disk type such as a hard disk drive (HDD),a compact disc read only memory (CDROM), a digital versatile disc (DVD),a solid state disk (SSD), and so on, and a card type such as a USBmemory (universal serial bus memory), a secure digital (SD) card, a minisecure digital (MSD) card, a micro secure digital (micro SD) card, asecure digital high capacity (SDHC) card, a memory stick card, a smartmedia (SM) card, a multimedia card (MMC), an embedded MMC (eMMC), acompact flash (CF) card, and so on.

The storage device 1310 may include a nonvolatile memory which storesdata semi-permanently. The nonvolatile memory may include a ROM (readonly memory), a NOR flash memory, a NAND flash memory, a phase changerandom access memory (PRAM), a resistive random access memory (RRAM), amagnetic random access memory (MRAM), and so on.

The controller 1320 may control exchange of data between the storagedevice 1310 and the interface 1330. To this end, the controller 1320 mayinclude a processor 1321 for performing an operation for, processingcommands inputted through the interface 1330 from an outside of the datastorage system 1300 and so on.

The interface 1330 is to perform exchange of commands and data betweenthe data storage system 1300 and the external device. In the case wherethe data storage system 1300 is a card type, the interface 1330 may becompatible with interfaces which are used in devices, such as a USBmemory (universal serial bus memory), a secure digital (SD) card, a minisecure digital (MSD) card, a micro secure digital (micro SD) card, asecure digital high capacity (SDHC) card, a memory stick card, a smartmedia (SM) card, a multimedia card (MMC), an embedded MMC (eMMC), acompact flash (CF) card, and so on, or be compatible with interfaceswhich are used in devices similar to the above mentioned devices. In thecase where the data storage system 1300 is a disk type, the interface1330 may be compatible with interfaces, such as IDE (Integrated DeviceElectronics), SATA (Serial Advanced Technology Attachment), SCSI (SmallComputer System Interface), eSATA (External SATA), PCMCIA (PersonalComputer Memory Card International Association), a USB (universal serialbus), and so on, or be compatible with the interfaces which are similarto the above mentioned interfaces. The interface 1330 may be compatiblewith one or more interfaces having a different type from each other.

The temporary storage device 1340 can store data temporarily forefficiently transferring data between the interface 1330 and the storagedevice 1310 according to diversifications and high performance of aninterface with an external device, a controller and a system. Thetemporary storage device 1340 for temporarily storing data may includeone or more of the above-described semiconductor devices in accordancewith the implementations. The temporary storage device 1340 may includea plurality of memory cells each including a switching element, whereinthe switching element includes a chalcogenide material including 0.1-5atomic percent (at %) of silicon, 15-22 at % of germanium, 30-35 at % ofarsenic and 40-50 at % of selenium. Through this, data storagecharacteristics of the storage device 1310 or the temporary storagedevice 1340 may be improved. As a result, operating characteristics anddata storage characteristics of the data storage system 1300 may beimproved.

FIG. 15 is an example of configuration diagram of a memory systemimplementing memory circuitry based on an implementation of thedisclosed technology.

Referring to FIG. 15, a memory system 1400 may include a memory 1410which has a nonvolatile characteristic as a component for storing data,a memory controller 1420 which controls the memory 1410, an interface1430 for connection with an external device, and so on. The memorysystem 1400 may be a card type such as a solid state disk (SSD), a USBmemory (universal serial bus memory), a secure digital (SD) card, a minisecure digital (MSD) card, a micro secure digital (micro SD) card, asecure digital high capacity (SDHC) card, a memory stick card, a smartmedia (SM) card, a multimedia card (MMC), an embedded MMC (eMMC), acompact flash (CF) card, and so on.

The memory 1410 for storing data may include one or more of theabove-described semiconductor devices in accordance with theimplementations. For example, the memory 1410 may include a plurality ofmemory cells each including a switching element, wherein the switchingelement includes a chalcogenide material including 0.1-5 atomic percent(at %) of silicon, 15-22 at % of germanium, 30-35 at % of arsenic and40-50 at % of selenium. Through this, data storage characteristics ofthe memory 1410 may be improved. As a consequence, operatingcharacteristics and data storage characteristics of the memory system1400 may be improved.

Also, the memory 1410 according to this implementation may furtherinclude a ROM (read only memory), a NOR flash memory, a NAND flashmemory, a phase change random access memory (PRAM), a resistive randomaccess memory (RRAM), a magnetic random access memory (MRAM), and so on,which have a nonvolatile characteristic.

The memory controller 1420 may control exchange of data between thememory 1410 and the interface 1430. To this end, the memory controller1420 may include a processor 1421 for performing an operation for andprocessing commands inputted through the interface 1430 from an outsideof the memory system 1400.

The interface 1430 is to perform exchange of commands and data betweenthe memory system 1400 and the external device. The interface 1430 maybe compatible with interfaces which are used in devices, such as a USBmemory (universal serial bus memory), a secure digital (SD) card, a minisecure digital (MSD) card, a micro secure digital (micro SD) card, asecure digital high capacity (SDHC) card, a memory stick card, a smartmedia (SM) card, a multimedia card (MMC), an embedded MMC (eMMC), acompact flash (CF) card, and so on, or be compatible with interfaceswhich are used in devices similar to the above mentioned devices. Theinterface 1430 may be compatible with one or more interfaces having adifferent type from each other.

The memory system 1400 according to this implementation may furtherinclude a buffer memory 1440 for efficiently transferring data betweenthe interface 1430 and the memory 1410 according to diversification andhigh performance of an interface with an external device, a memorycontroller and a memory system. For example, the buffer memory 1440 fortemporarily storing data may include one or more of the above-describedsemiconductor devices in accordance with the implementations. The buffermemory 1440 may include a plurality of memory cells each including aswitching element, wherein the switching element includes a chalcogenidematerial including 0.1-5 atomic percent (at %) of silicon, 15-22 at % ofgermanium, 30-35 at % of arsenic and 40-50 at % of selenium. Throughthis, data storage characteristics of the buffer memory 1440 may beimproved. As a consequence, operating characteristics and data storagecharacteristics of the memory system 1400 may be improved.

Moreover, the buffer memory 1440 according to this implementation mayfurther include an SRAM (static random access memory), a DRAM (dynamicrandom access memory), and so on, which have a volatile characteristic,and a phase change random access memory (PRAM), a resistive randomaccess memory (RRAM), a spin transfer torque random access memory(STTRAM), a magnetic random access memory (MRAM), and so on, which havea nonvolatile characteristic. Unlike this, the buffer memory 1440 maynot include the semiconductor devices according to the implementations,but may include an SRAM (static random access memory), a DRAM (dynamicrandom access memory), and so on, which have a volatile characteristic,and a phase change random access memory (PRAM), a resistive randomaccess memory (RRAM), a spin transfer torque random access memory(STTRAM), a magnetic random access memory (MRAM), and so on, which havea nonvolatile characteristic.

Features in the above examples of electronic devices or systems in FIGS.11-15 based on the memory devices disclosed in this document may beimplemented in various devices, systems or applications. Some examplesinclude mobile phones or other portable communication devices, tabletcomputers, notebook or laptop computers, game machines, smart TV sets,TV set top boxes, multimedia servers, digital cameras with or withoutwireless communication functions, wrist watches or other wearabledevices with wireless communication capabilities.

While this patent document contains many specifics, these should not beconstrued as limitations on the scope of any invention or of what may beclaimed, but rather as descriptions of features that may be specific toparticular embodiments of particular inventions. Certain features thatare described in this patent document in the context of separateembodiments can also be implemented in combination in a singleembodiment. Conversely, various features that are described in thecontext of a single embodiment can also be implemented in multipleembodiments separately or in any suitable subcombination. Moreover,although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Moreover, the separation of various system components in theembodiments described in this patent document should not be understoodas requiring such separation in all embodiments.

Only a few implementations and examples are described. Otherimplementations, enhancements and variations can be made based on whatis described and illustrated in this patent document.

What is claimed is:
 1. A chalcogenide material comprising 0.1-5 atomicpercent (at %) of silicon, 15-22 at % of germanium, 30-35 at % ofarsenic, and 40-50 at % of selenium.
 2. The chalcogenide material ofclaim 1, wherein content of silicon is 0.5-4 at %.
 3. The chalcogenidematerial of claim 1, wherein content of germanium is 17-20 at %.
 4. Thechalcogenide material of claim 1, wherein content of arsenic is 31-34 at%.
 5. The chalcogenide material of claim 1, wherein content of seleniumis 43-48 at %.
 6. An electronic device comprising: a switching elementincluding a chalcogenide material, the chalcogenide material including0.1-5 atomic percent (at %) of silicon, 15-22 at % of germanium, 30-35at % of arsenic, and 40-50 at % of selenium; a first electrodeelectrically coupled to the switching element; and a second electrodeelectrically coupled to the switching element.
 7. The electronic deviceof claim 6, wherein content of silicon is 0.5-4 at %.
 8. The electronicdevice of claim 6, wherein content of germanium is 17-20 at %.
 9. Theelectronic device of claim 6, wherein content of arsenic is 31-34 at %.10. The electronic device of claim 6, wherein content of selenium is43-48 at %.
 11. An electronic device comprising a semiconductor memorydevice, the semiconductor memory device including a first memory cellthat includes a first switching element, wherein the first switchingelement includes a chalcogenide material including 0.1-5 atomic percent(at %) of silicon, 15-22 at % of germanium, 30-35 at % of arsenic, and40-50 at % of selenium.
 12. The electronic device of claim 11, whereinthe semiconductor memory device further includes: a second memory cellincluding a second switching element, the second switching elementhaving a chalcogenide material including 0.1-5 atomic percent (at %) ofsilicon, 15-22 at % of germanium, 30-35 at % of arsenic, and 40-50 at %of selenium, and wherein the first memory cell and the second memorycell further include a first memory layer and a second memory layer,respectively, each of the first and second memory layers switchingbetween different resistance states according to a voltage or a currentapplied thereto.
 13. The electronic device of claim 12, wherein thefirst switching element and the second switching element control accessto the first memory layer and the second memory layer, respectively. 14.The electronic device of claim 11, wherein the semiconductor memorydevice includes a plurality of memory cells including the first memorycell, wherein the semiconductor memory device further includes: aplurality of first lines disposed between a substrate and the pluralityof memory cells, each of the plurality of first lines extending in afirst direction; and a plurality of second lines disposed over theplurality of memory cells, each of the plurality of second linesextending in a second direction that crosses the first direction, andwherein the plurality of memory cells are disposed at respectiveintersections of the first lines and the second lines.
 15. Theelectronic device of claim 11, wherein the semiconductor memory devicefurther includes a capping layer disposed over at least side surfaces ofthe first memory cell.
 16. The electronic device of claim 11, content ofsilicon is 0.5-4 at %.
 17. The electronic device of claim 11, whereincontent of germanium is 17-20 at %.
 18. The electronic device of claim11, wherein content of arsenic is 31-34 at %.
 19. The electronic deviceof claim 11, wherein content of selenium is 43-48 at %.
 20. Theelectronic device according to claim 11, further comprising amicroprocessor which includes: a control unit configured to receive asignal including a command from an outside of the microprocessor, andperforms extracting, decoding of the command, or controlling input oroutput of a signal of the microprocessor; an operation unit configuredto perform an operation based on a result that the control unit decodesthe command; and a memory unit configured to store data for performingthe operation, data corresponding to a result of performing theoperation, or an address of data for which the operation is performed,wherein the semiconductor memory is part of the memory unit in themicroprocessor.